Your dad's neighbor just called to tell you that your 79-year-old father sideswiped his parked vehicle and nearly hit a child standing nearby. Was it an isolated slip-up or the sign that it's time for your dad to think about giving up his car keys? More importantly, how do you begin the discussion about such a potentially volatile subject?

Sensitive issues like this prompted Home Instead Senior Care, a company serving Sacramento, Placer, Nevada and El Dorado counties to launch a public education campaign called the "40-70 Rule."

This campaign will help adult children begin to address difficult issues with their parents such as driving, finances, independence and even romance.

"The 40-70 Rule means that if you are 40 or your parents are 70, it's time to start the conversation about some of these difficult topics," says Buck Shaw, owner of the local Home Instead Senior Care office.

The campaign revealed that nearly one-third of adults in the U.S. have a major communication obstacle with their parents that stems from continuation of the parent-child role. In other words, it can be difficult to get the conversation going because the child is still in a child rather than adult role with their aging loved one.

"Because of this obstacle, adult children may wait until an emergency or crisis happens before talking to parents," says Shaw. "Our goal with the 40-70 campaign is to provide practical ways for adult children to talk to their parents now. We've seen lack of communication lead to misuse of medications, self-neglect and accidents."

At the center of the campaign is a guide of conversation starters for sensitive senior-care subjects, which is available free from the local Home Instead Senior Care office.

The guide was compiled with the assistance of Jake Harwood, Ph.D., national author and communication professor from the University of Arizona, who is the former director of that school's graduate program in gerontology.

Starting conversations early is particularly important for end-of-life issues such as power of attorney and wills, says Harwood, author of "Understanding Communication and Aging." Other topics may need to be addressed as well, he adds.

"On the earlier driving instance, you could say, 'Hey Dad, Fred from next door called to tell me about your accident. What happened?'" Harwood says. "Then take the opportunity to drive with your parent. Even a short drive would help you gauge your dad's skills and deficits."

Such conversations should be broached with care, Harwood adds.

"It's crucial to begin these conversations assuming 'if' rather than 'when.' Many older adults continue to drive safely as they age. So personal circumstances should determine how much discussion needs to occur," he says.

In general, the Home Instead Senior Care survey found that Boomers have the most difficulty talking with their parents about independence issues, such as continuing to live in their own home and that their parent's desire to remain independent makes it challenging to address such sensitive issues as health (28 percent) and money (21 percent). The fact that many of these families are still in a parent-child rather than a peer-to-peer role makes the conversations even more difficult.

"It takes two to tango," Harwood explains. "If an adult child always turns first to the parent in times of trouble, regularly needs money from the parent, or calls the parent every time there's a crisis in the child's romantic life, then they can expect the parent to continue acting out the parenting role.

"On the other hand, if the child becomes truly independent and stops acting out these behaviors, then the parent may be more likely to relinquish the parent role," he continues. "So adult children should be aware of the sorts of behaviors they are engaging in, which may cause their parents to act parentally."

Physical space and place also influence communication, Harwood says.

"A family reunion on a major holiday may well trigger a lot of memories and associations of childhood for all involved, not just the parents," he says.

Harwood says adult children may need to "mix things up a little" if the parental behaviors are a problem.

"This might be achieved by taking a more active role in cooking the dinner or taking the parent out to the mall to buy them a gift just to change the dynamic and the setting in a positive way," he says.

The bottom line is to keep talking, because the parent-child conversation can be so important in helping seniors adapt to changing life circumstances, say both Harwood and Shaw.

Good communication also is vital to helping families know when it's time to seek additional resources.